In a wide variety of situations and circumstances, it is convenient and common to provide a plurality of strategically-located audible signals which may be used for any of a wide variety of purposes frequently including one or more of the following: background music; paging; announcements; advertisements; and a variety of alarms or testing signals. Furthermore, there are situations and circumstances wherein it is desired to be able to apply the audible signals to less than the total plurality of audio devices. As the art has developed and various features have been made available, consumers have requested systems embodying a wider and wider variety and combination of features. Systems of the general nature to which reference has been made may find utility in a large department store to provide background music in at least selected areas during part of the time when the system is not otherwise engaged. At some other time, it may be appropriate to have an announcement made concerning an event or conditions and at other times, it may be desirable to be able to produce alarm tones in response to detected conditions and it is also desirable to be able to produce a wide variety of alarm tones in response to manual actuation at a keyboard. In addition, it is desirable to be able to include testing facilities to verify operation of the system and all features therein. Such systems may also find utility in hospitals, office buildings, high-rise residences and a variety of other applications with which those familiar with the use of systems of the character described are familiar.
In a system which is capable of providing a variety of tone signals and services, it is desirable to be able to assign a priority concerning the tone signal to be transmitted in the event that, in the absence of a control means, more than one signal would be broadcast concurrently. The central or control station is herein referred to as a console or control console and all automatic or manual requests for the transmission of audible signals to the remote stations are received at or originated from such console. The use of control consoles is well known in the art.